"If everything would go as planned, he would be in Vance's spot," Marlins manager Don Mattingly said. "We're going to put Vance in the bullpen, and then go from there, unless something would go wrong."
Locke was shut down from throwing the first week of Spring Training and has since been building up arm strength. Locke was a candidate in the spring to be the club's fifth starter or to serve in a long-relief role.
But with the rotation scrambled with Adam Conley at Triple-A New Orleans and Tom Koehler on the disabled list with right shoulder bursitis, Miami needs someone to eat innings.
"Very excited," Locke said. "My rehab went great. It was more important to me to come out of each rehab outing healthy and strong than the results of the game. I'm really eager to get back up."
Locke made four rehab assignment starts -- two with Class A Advanced Jupiter and two with Double-A Jacksonville. He posted an ERA of 1.77 with 22 strikeouts and two walks in 20 1/3 innings.
"My mentality was go out there and try to give the guys a chance to win, the same as I'd do here," Locke said. "You can't pitch down to the level. You can't treat it any differently. Just very comfortable with where I am right now."
• Right-handed reliever Junichi Tazawa (right rib cartilage inflammation) is throwing with minimal discomfort and is progressing towards being ready for a rehab assignment. No date has been set yet.
"I feel I can go any time, but obviously, we're on a schedule," Tazawa said. "We're going to follow that schedule and get back."
One potential holdup is the Japanese-born Tazawa no longer has his personal interpreter. On Monday, he used Allen Turner, Ichiro Suzuki's translator, to speak with reporters. Because of the language barrier, Tazawa would need someone to interpret for him on a rehab assignment.
• Braxton Garrett, the seventh overall pick in the 2016 Draft and Miami's No. 1 prospect according to MLBPipeline.com, has been shut down temporarily due to left elbow soreness. Garrett exited a May 25 start for Class A Greensboro after 1 2/3 innings, allowing four runs (two homers) on six hits in his fourth start for the club. The Marlins are confident the 19-year-old will be fine with some rest. Garrett is no longer on Greensboro's roster, he is now on short-season Class A Batavia, which opens on June 19. The Marlins are limiting Garrett's total innings this season to about 100.